PORTLAND, Maine — One year after nearly being forced to close, the Portland Community Free Clinic is no longer on life support, but remains in serious condition.

The clinic, at 103 India St., provides no-cost medical care to more than 500 Cumberland County residents who can’t afford health insurance, but earn too much to qualify for Medicaid or other low-income health-care benefit programs.

With only a few employees, the clinic is staffed by 100 volunteer physicians, nurses, receptionists and others. But since its creation 20 years ago, it has also depended on external funding.

The clinic faced possible closure in December 2012 after losing financial support from Mercy Hospital and the city.

Mercy, which had been suffering financial difficulties of its own, stopped its annual contribution of about $200,000 in 2011. Emergency funding from the city dried up a year later.

“I am confident that we can make our payroll and expectations until the first of July,” clinical programs director Dr. Caroline Teschke said last week.

Since last year’s crisis, Teschke said, the clinic has had “modest” success obtaining support through additional grants, individual donations, and fundraising events such as a holiday concert last Saturday at St. Ansgar Lutheran Church, in the Rosemont neighborhood. A charitable auction is planned for next March.

The clinic also continues to receive in-kind aid from the city, which provides office space and insurance coverage, and from Mercy, which helps out with free laboratory services.

In addition, the clinic has applied to become an independent nonprofit organization, a status that would provide tax and legal benefits. After receiving free help with the application process from Portland law firm Verrill Dana, Teschke said she expects to receive approval from the federal government sometime next year.

But meanwhile, the need for the clinic’s care “is in no way diminished,” she said. In fact, it may be increasing.

Unlike other public health clinics in the city, the Free Clinic specializes in caring for the working poor, a population that is overlooked amid the much-publicized debate over the federal Affordable Care Act, also known as “Obamacare.”

The ACA was touted as reducing the number of Americans without health coverage by expanding eligibility for Medicaid, and providing subsidies to help those who were ineligible to buy insurance through state-run health exchanges.

But the act doesn’t help many people in the middle: those who are ineligible for Medicaid, but for whom the subsidies aren’t enough. In Maine, this gap in coverage is compounded by the state’s refusal to participate in the optional expanded Medicaid coverage.

And the problem is about to get worse. On Jan. 1, 2014, as many as 25,000 state residents will lose their Medicaid coverage, called MaineCare, because of eligibility changes made two years ago.

“The Affordable Care Act was written with the assumption that every state would take the expansion. There is nothing for [the working poor],” Teschke said. “… A [health] plan that costs $300 with a subsidy may as well be $3,000.”

Clinic patients can earn up to 250 percent of the federal poverty level, which for a single person represents an annual income of about $27,000. That range accommodates artists, small-business owners, restaurant workers and others who eke out a living without access to health care.

“We see people between jobs, but we also see a lot of people who are just piecing [an income] together and don’t have insurance or even sick days,” public health nurse Bob Barrett said.

One such patient is Erin Curren, of Westbrook, who works as an actor, a movement teacher and a Bowdoin College lecturer. But none of her jobs provide health benefits. So Curren recently turned to the clinic for a routine physical exam.

“I don’t know where I would have been able to get such a comprehensive check-up if the clinic weren’t here,” she said. “I felt like this was as good care as I’ve gotten when I did have insurance.”

Despite the continued demand for the clinic’s services and its uncertain funding, Teschke said she’s cautiously optimistic it can succeed by being “flexible and nimble.”

Like its patients, the clinic is practiced at making the most of scant resources, relying on its volunteers, obtaining $150,000 in free medication each year for patients, and even turning to online bulletin board Craigslist.com to seek donations of medical equipment.

As a result, program coordinator Leslie Nicoll estimated, every dollar of the clinic’s budget ultimately provides about $15 of patient care.

“We already do so much with so little … a small amount of money parlays into a lot of services,” Teschke said. “Even if [our budget] is only a shoestring, it still has a lot to hold up.”